4.3.3 Human Pressure on Water Resources | SL IB Geography Revision Notes 2019

Impact of Population & Economic Growth on Water Quality

The growth of the world population increases the demand for water
Population growth is unevenly distributed and so the need for increased water supply is also uneven
Urban areas experiencing a rapid increase in population usually experience the most water stress
The quantity of water currently being used for all purposes is over 3700 cubic kilometres per year
The growth of population leads to a greater demand for water for all uses:

world-water-demand

Demand for water

Agriculture is the largest user of water:
- Consumes over two-thirds of water drawn from rivers and lakes
- Water for crop irrigation has increased by 70% since 1960
Industry uses 22% of available water
The domestic sector uses 8%
These all impact on water quality and availability
Many rivers have become polluted, which makes them unusable for human needs

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Sources of water pollution

Rivers which are contaminated by industrial waste can cause algae blooms
- This makes the water unsafe to be used by humans
- The toxins produced by the algae can kill wild animals and livestock
Many fish deaths are occurring because of the increase in temperatures in rivers
Overuse of aquifers can result in reduced water supply
There are many examples of water quality issues around the world
- China’s rapid economic growth has meant that over 70% of the country’s rivers cannot be used for human consumption
- Lead poisoning in Flint, USA, because of industrial pollutants in the river waters

The Aral Sea is an endorheic lake which is located in Asia
The lake is transboundary because half lies in Uzbekistan and half in Kazakhstan
Rivers enter the lake from Amu Darya and Syr Darga
In 1997, the Intergovernmental Panel on Climate Change highlighted the Aral Sea as a case study for what happens when lakes are misused
In 1960, the lake was the world’s 4th largest inland water body

Large-scale irrigation systems were introduced in the 1930s
Between 1960 and 1980, the area was known for the cotton industry
- This required increased irrigation from the Amu Darya and Syr Darga rivers
The population increased from 14.1 million in 1960 to 47 million in 2008
According to UNESCO, there are now 51 million people living in the Aral Sea basin
By September 2011, the lake had separated into four parts and had shrunk in area by 85% and volume by 92%

The fishing industry, which used to employ 40,000, collapsed
Camel farming decreased because the grass that camels ate was too salty due to the wind blowing salt from the drying up lake
Factories in the area which used the lake to transport their goods could no longer use the lake as a trade route, causing rising unemployment

According to scientists, the Aral Sea could dry up in the next 20 years, which would affect drinking water supplies
Due to highly toxic winds, there has been an increase in respiratory illnesses caused by dust from fertilizers being spread by wind

The Great Artesian Basin (GAB) is situated in central Australia
One of the world’s largest groundwater systems, which supports a variety of ecosystems and springs
The basin is nearly 1.7 million square kilometres
There has been little sustainable management of the basin
- Leading to much wastage of water through evaporation and seepage
Water wastage damages the environment through land and water salinization
Agriculture has dominated groundwater extraction
Water extraction for mining and oil projects has been increasing
The Olympic Dam mining project has been extracting groundwater since 1983

More than 180,000 people rely on the groundwater from the basin
Over 120 towns are supported through the basin including both homes and businesses
Aboriginal and Torres Strait Islander people have been using the basin for over 60,000 years
In August 2018, the Australian government announced The Improving Great Artesian Basin Drought Resilience program worth up to $26.7 million